Roller folding head and method for folding a flange

ABSTRACT

The invention relates to a roller folding head. Roller folding heads are used, for instance, when fixing the frame of a sliding roof in an opening in the roof of a vehicle. In order to do this quickly and automatically, the roller folding head is provided with at least two pairs of rollers ( 8, 10; 9, 11  or  20, 22; 21, 23 ), each pair of rollers ( 8, 10; 9, 11  or  20, 22; 21, 23 ) consisting of a pressing roller and a counter roller which interact in order to bend a flange ( 32 ) along a folding line at a specific angle. The folding process is carried out in several stages, one flange being crimped around another flange in a series of partial steps at an angle of 180°. One pair of rollers is provided for each step, at least two thereof being arranged on a roller folding head.

The invention relates to a roller folding head.

Such roller folding heads, which are coupled with a robotic arm and areguided by said arm, are used, e.g., in the automobile industry in orderto connect sheet metal together by means of folding operations. One areaof application is, for example, the connection of the frame of a slidingroof with the edge of an opening in the roof of a vehicle.

A roller folding head that is suitable for such an operation must beadapted to the respective space requirements in the individual case andmay not introduce any forces into the body of the vehicle during thefolding operation. In addition, there should be as few swappingoperations as possible.

The invention provides for solving the problem a roller folding head forfastening to a robotic arm with two pairs of rollers, each pair ofrollers comprising a pressure roller and a counter-roller, both of whichinteract to bend a flange at a specific angle along a folding line, andwith a base body and a carriage that can slide along said base body, thepressure rollers being mounted on the carriage so as to rotate.

Since, according to the above, two pairs of rollers are disposed at theroller folding head, at least two successive folding operations can becarried out. By means of the carriage, to which the pressure rollers arefastened, the pressure rollers are moved into the respective workingposition.

The two flanges, which are supposed to be connected together by means ofthe folding operation, are, first of all, parallel to each other, theone flange projecting beyond the other. The projecting segment of theone flange is gradually beaded 180° about the other flange in severalsteps. To carry out the first step, the pressure roller of the firstpair of rollers exhibits a conically expanding folding segment, which isforced against the projecting segment and bends this projecting segmentto about 45°. So that the counter-roller of this pair of rollers can beguided behind the bent-over segment, it is pivot-mounted on anothercarriage which can be moved relative to the base body. Thecounter-roller of the second pair of rollers takes over the beadingoperation at another 45° and, therefore, does not have to be heldmoveably at the base body. Rather it is mounted at the base body in sucha manner that it cannot slide.

Preferably the two carriages are arranged at the base body in such amanner that they can be moved perpendicularly in opposite directions.The result is a compact construction of the roller folding head.

It is true that each pair of rollers can be formed by one pressureroller and one counter-roller each, both of which are assigned only tothis pair. Hence, four pairs of rollers yield 8 individual rollers. Toreduce the number of rollers, it is provided that one pressure rollercan be assigned to any arbitrary counter-roller to form a pair ofrollers. Thus, the system of roller pairs can comprise, for example, twopressure rollers and four counter-rollers, where one of the pressurerollers interacts in succession with three of the counter-rollers.

Preferably these counter-rollers are coupled with one revolver head(24), which is connected to the base body (2).

Secondly, the invention relates to a method for folding a flange in foursteps, wherein at least three different pairs of rollers are used withthe goal being a curl of 180°.

As to be explained in detail in the embodiment, the first pair ofrollers can be definitely used both for the first and for the finalfourth folding step. In principle two procedures are possible. First,two roller folding heads with different pairs of rollers can be used.Secondly, a single roller folding head can be used, where thecounter-roller of a pair of rollers can be swapped by means of achanging device so that a total of four different pairs of rollers isconceivable.

The invention is explained in detail with reference to the embodimentsshown in the figures.

FIG. 1 depicts a first design of a roller folding head 1. This headcomprises a U-shaped base body 2. A flange plate 3 for fastening to arobotic arm is mounted on a leg of the base body 2. On the side of thebase body 2 opposite the flange plate 3 there is a carrier 4 at a firstpneumatically moveable carriage 5.

The T-shaped carrier 4 has two arms 6, 7, of which the one arm 6exhibits a first pressure roller 8, and the other arm 7 exhibits asecond pressure roller 9. One counter-roller 10, 11 acts together withboth pressure rollers 8, 9. The first counter-roller 10, which interactswith the first pressure roller 8, is disposed on another carriage 12,which is held moveably at the base body 2, the two carriages 5, 12enclosing a right angle. The second counter-roller 11 is pivot-mounteddirectly on the end of one leg of the base body 2. Moreover, the basebody 2 exhibits a force absorbing roller 13.

For the method for folding a flange (described below), a second rollerfolding head is used that corresponds to the roller folding head,depicted in FIG. 1. The second roller folding head carries a third and afourth pressure roller 20, 21, as well as a third and fourthcounter-roller 22, 23, where, however, the fourth counter-roller 23 isheld at the base body 2 in such a manner that it cannot be displaced. Inaddition, the rest of the carriage 12 is replaced by a wedge-shapedholder.

In place of the two roller folding heads, one roller folding head canalso be used in accordance with FIG. 2. In this embodiment, the second,the third and the fourth counter-roller (11, 22, 23) are mounted on arevolver head 24, which forms a changing device, on the base body 2. Thesecond pressure roller 9 interacts with one of the three counter-rollers(11, 22, 23) as a function of the position of the revolver head 24, sothat a second, third or fourth pair of rollers is formed.

To illustrate how the two roller folding heads of FIG. 1 or the rollerfolding head with the revolver head 24 of FIG. 2 work, reference is madeto FIGS. 3 a to 3 d. They show the connection of a roof 30 to the frame31 of a sliding roof. The roof 30 exhibits an opening, the opening edgebeing set up so as to form a flange 32, which runs approximatelyperpendicular to the surface of the roof 30.

The frame 31 ends in a leg 33, which runs parallel to the flange 32. Theflange 32 is higher than the leg 33, thus producing a connection betweenthe roof 30 and the frame 31 in that the projecting portion of theflange 32 is bent 180°. around the leg 33. This is done in four foldingoperations, which are shown little by little in the FIGS. 3 a to 3 d. Ineach step the projecting portion of the flange 32 is bent overapproximately 45°. For each step, a pair of rollers is provided.

In the first step, according to FIG. 3 a, the first pressure roller 8works together with the first counter-roller 10. The first pressureroller 8 exhibits a conically expanding folding segment 34, the conicityof which corresponds to the intended bending of the flange 32. Acylindrical segment of the first pressure roller 8 rests against theflange 32. To brace against the forces introduced into the body of thecar by this operation, the first counter-roller 10 runs inside along theleg 33. Thus, no forces are introduced into the frame 31 or into theroof 30.

In the second step according to FIG. 3 b, the second pressure roller 9works together with the second counter-roller 11. The second pressureroller 9 is a cylinder without a conical segment. The counter-roller 11,also called the folding roller, which is positioned at a slight angle,pushes the flange 32 down another 45°.

In the third step according to FIG. 3 c, either a second roller foldinghead or a roller folding head of FIG. 2 is used. However, in this casethe revolver head 24 is rotated further by one position, so that now thethird counter-roller 22 is used. In this design the third pressureroller 20 is identical to the second pressure roller 9.

In the final operation of FIG. 3 d, a fourth pressure roller 21 or afourth counter-roller 23 is used. The fourth pair of rollers is formedeither, according to FIG. 1, at a second roller folding head or isproduced by rotating the revolver head 24, according to FIG. 2. Thefourth pressure roller 21 in turn is depicted by the second pressureroller 9.

The individual positions are reached by rotating always the entireroller folding head 1 and by guiding the carrier 4 into the respectivefolding position by means of the carriage 5.

Thus, the method is also characterized in that the beading operationtakes place in four steps, where at least in the first step the twoflanges are pushed against each other by means of one pressure rollerand one counter-roller; and a conically tapering segment of the pressureroller provides for one portion of the bead, and that in the subsequentsteps the subsequent portions of the bead are produced by the respectivecorrespondingly oriented counter-rollers. Since in the subsequent stepsthe pressure roller has essentially the task of guiding the rollerfolding head at the flange, it can be a single cylindrical body, whichrests against and then rolls off that segment of the flange that is notto be beaded. The counter-rollers, provided with a conically taperingsegment, are oriented relative to the flange in accordance with thedesired progress in the beading operation.

List of Reference Numerals

-   1 roller folding head-   2 base body-   3 flange plate-   4 carrier-   5 carriage-   6 arm-   7 arm-   8 first pressure roller-   9 second pressure roller-   10 first counter-roller-   11 second counter-roller-   12 carriage-   13 force absorbing roller-   20 third pressure roller-   21 fourth pressure roller-   22 third counter-roller-   23 fourth counter-roller-   24 revolver head-   30 roof-   31 frame-   32 flange-   33 leg-   34 folding segment

1. A roller folding head for fastening to a robotic arm comprising abase body, a carriage adapted to slide along said base body, and twopairs of rollers, denoted as a first pair and a second pair, each pairof rollers, comprising a pressure roller and a counter-roller, both ofwhich interact to bend a flange at a specific angle along a foldingline, one of said pressure rollers being rotatably mounted on thecarriage.
 2. A roller folding head, as claimed in claim 1, furthercomprising a second carriage adapted to be moved relative to said basebody, wherein the counter-roller of the first pair of rollers is mountedimmoveably on the base body; and the counter-roller of the second pairof rollers is mounted rotatably on said second carriage.
 3. A rollerfolding head, as claimed in claim 1, wherein both counter-rollers aremounted rotatably in immoveable bearings on the base body.
 4. A rollerfolding head, as claimed in claim 2, wherein both carriages are arrangedon the base body such that they can be moved perpendicularly in oppositedirections.
 5. A roller folding head, as claimed in any one of thepreceding claims, wherein one pressure roller is adapted to cooperatewith a plurality of counter-rollers.
 6. A roller folding head, asclaimed in claim 5, further comprising a revolver head connected to thebase body wherein the counter-rollers are coupled with said revolverhead.
 7. A four-step method for folding a flange 180° around anotherflange running parallel to the first flange to form a bead, comprisingpushing the two flanges against each other by means of one pressureroller and one counter-roller; wherein a conically tapering segment ofthe pressure roller provides for one portion of the bead, and producingsubsequent portions of the bead by respective correspondingly orientedcounter-rollers.
 8. A four-step method for folding a flange at 180°,wherein at least three different pairs of rollers are used that arecarried by a roller folding head, according to one of the claims 1 to 4.9. A four-step method for folding a flange at 180°, wherein at leastthree different pairs of rollers are used that are carried by a rollerfolding head, according to claim
 5. 10. A four-step method for folding aflange at 180° C., wherein at least three different pairs of rollers areused that are carried by a roller folding head, according to claim 6.